There may be a very good reason why it's so hard to treat heart disease in women

Their hearts could look completely different, even if
they're the same age.martin/Flickr

As we get older, our heart, the
muscle that keeps our blood pumping, changes dramatically — and a
recent study finds that much of the change often falls
along gender lines.

The
long-term study looked at 5,000 participants aged 45-84 over
a 10-year period who were taking part in the Multi-Ethnic Study
of Atherosclerosis, a study sponsored by the National Institute
of Health’s NationalHeart Lung and Blood
Institute.

They measured for a number of
different heart factors, but the biggest thing they saw was that
male hearts tended to get thicker over time, while women's often
became thinner over the same time period. For both, the cavity
around the heart, called the pericardial cavity, shrinks.

It wasn't a hard and fast rule,
though it was a strong finding: The researchers did see that
there were women whose heart muscle got thicker, while some men's
hearts got thinner. But for the most part, the researchers saw a
consistent thickening for men, and a slight decrease for
women.

But the vast majority of medications we have to address
these physical changes are designed to treat the ones typically
found in aging men.

A natural conclusion would be to
say sex hormones must play a role in this. Sex hormones,
like
testosterone and estrogen are involved in muscle
developmentthroughout
a person’s life. But could differences in sex hormones have this
much of an effect on the heart muscle? Study author and Johns
Hopkins professor of medicine and radiology Joao Lima told
Business Insider that's "the million dollar question."

"If we unlock the mechanism we
could treat men and women differently," Lima said.

That could drastically lower the
amount of women who die of heart disease, said
Lima.Over the past few decades the rate of heart
disease among men in the United States hassteadily dropped since the
1980s,thanks to preventative measureslike making lifestyle changes to
diets and smoking habits and medications like beta
blockers.Yet it hasn’t done so with women. Heart
disease remains the
number-one killer of American women.